YH35324 is an Fc fusion protein of the IgE series, ‘IgE Trap’, which is a form that fuses the extracellular domain of the IgE receptor (FcεR1) with a hybrid Fc. Its main mechanism of action is to reduce the level of free IgE in the blood to improve allergy symptoms. IgE mediates allergic reactions in the body through immune cells such as eosinophils and mast cells. Therefore, suppressing IgE to alleviate allergies, the existing allergy treatment ‘Xolair (omalizumab)’ is being marketed.
Yuhan Corporation is developing YH35324 as a treatment for IgE-mediated allergic diseases such as chronic urticaria (CSU), atopic dermatitis, allergic asthma, and food allergies. YH35324 has strong IgE binding power compared to Xolair and can suppress IgE even in patients with autoantibodies who do not respond to existing drugs, targeting patients with high IgE levels and those who are non-responsive to Xolair. Additionally, YH35324 does not bind to the Fcγ receptor, which is expected to lower the risk of anaphylaxis that can occur with the administration of existing IgE antibody drugs.
Yuhan Corporation has published the results of the ‘first-in-class’ Phase 1 clinical trial for Proof of Concept (PoC) of YH35324 in patients with chronic urticaria in the International Journal of Immunopharmacology. According to the study, YH35324 showed more potent and sustained IgE suppression activity compared to Xolair and placebo, especially in patients with elevated IgE levels (>700 IU/mL), demonstrating a superior safety profile and more potent and sustained free IgE suppression activity compared to existing treatments. This Phase 1a trial was conducted from September 2021 to January 2023 in the allergy departments of four university hospitals in Korea, involving a total of 68 healthy subjects, patients with mild allergic rhinitis and atopic dermatitis, and patients with food allergies and urticaria.
Yeol Hong Kim, President of R&D at Yuhan Corporation, stated, “The Phase 1a trial was successfully completed, showing the potential of the drug as a treatment even in patients with elevated IgE levels, which is a differentiator from existing treatments. We will make every effort to successfully enter Phase 2 clinical trials.”